Adjustable crank.



M. LEITCH & S. H. HALL.

ADJUSTABLE CRANK.

APPLICATION FILED FEB. 25, I914. 1,159,054.

Patented Nov. 2, 1915.

I I! LU! WITNESSES:

lA/KE/VWRS DGRAPM (10., WASHINGTON. n

MEREDITH LEITCH AND SELDEN HQ HALL, or POUGHKEEPSIE, NEW some .assrenons TO THE iDE LAVAL SEPARATOR COMPANY, A CORPORATION on NEW JERSEY.

ADJUSTABLE CRANK.

To all whom it may concern:

Be it known that we MEnEDITH LEI ToH and SELDEN H. HALL, citizens of theUnited States, residing atPoughkeepsie, county of Dutche-ss, and State of New York, have invented a new'and useful Improvement in- Adjustable Cranks, of which the following,

is a full, clear, andexact description, reference being had to the accompanying drawings, which form a part of thisspecification.

In many machines operated bymanual power, of which cream separators are one class, there is a large inertia making the start hard and yet after reaching full speed these machines run with little power. a long crank is used on such a machine the eifort needed to start it is much less than with a short one, but after reaching full speed the exertion of movingthebody to swing the large circle is more tiring than the work needed to. dr vejthe ma'chme,

operation after full speed has been attained.

The object of this invention is to-provide a, crank that may be adjusted to fit eitherof the above mentioned conditions. i r

A second ob ect s to provide a crankthat may. be changed fromthe length for one condition to the length for the other condition without stoppingthe machine.

A third object isto provide automatic means for looking it at either position, while it is being used, f

A' fourth object isto provide automatic means to release the look when theappli'ca tion of power'to the crank ceases.

In ;-the preferred embodimentof our invention. we make use of a hub fastened to the shaft to be driven and on this hub provide a centernot the center of the shaft; about which the crank may be rotated in-v dependent of the rotation of the shaft. In-

this hub we provide a dog that is 'adaptedto engage one or the other oftwo'ratchetteeth on the crankfmember; said teeth being so placed that with one of them in engagement with the dog the crank is on the side of its center, away from. the crank shaft center,

While with the other tooth engagedwith'the.

' Specification of Letters Patent.

7 dog the crank ison thesideiof its center nearest to the center; ofthe shaft. 7 In the drawings: Figure l is a side view of a crank embodying our invention. Fig.

2- is a sectional view on the center line of to Fig; 2' showing an alternative. construc tion embodyingthe same principles as those shown in the other figures.

a is a shaft to be driven'by the crank. I

6 is a hub fastenedtothe shaft a by a v I PatentedNov. '2 1 791. 5, 7

Application filed February 25, 1914. Serial No. 820,862; v

set screw 0 and having a disk (Z the center 7 of which does not coincide with the center of thefshaft. 1

eis a bearing, with itscenter coinciding v with-the center of the diskd, about which the crank may rotate. f is thecrankarm;

disk

- h is a shoulder on the bearingand holds thedisk gsagainst the disk d.

f i is a dog or pin-forced outward by spring j from a, socket in the huh I).

At is and Zare ratchet teeth inthedisk These-teeth are so shapedas to: allow/afree, movement of the crank backward relative havingla disk 9 adapt-l ed to. fit; over the bearing and against the to the vshaftbut t oengage the dog and p rev vent forward movement. a

The operation is as follows: The operator turns the crank arm backward,,relatlve -to theshaft, until the crank center (2'. 6., center oftheb'earing e) is-between the shaft center and the free-end of the'arml The dog. z' will then engage the ratchet. tooth 1c and,

turning the crank forward willstartthev ma chine with a long crank arm Afterthe de sired speed has' been reached the operator holds the crankstationary while the shaft makes one half revolution. Notice of the completion of the-half turn will becgiven by,

the click of the dog 2' entering the ratchet; tooth l. The shaftcenter is now .between I the crank center, orcenter of bearing 6, and"v the free end of the crank arm, affording arelatively short arm, and the machine may be driven in this way as long as it .isfdesiredg to do-so.; Q.

In themodification shown in the hub b. is eccentrically shaped 'and is secured to the shaft a by means of a set screw 0.

The hub is provided at one end with a circumferential flange and against the other end of the hub and the end of the shaft, which are flush one with another, is applied a disk or plate m, which is secured to the shaft by means of the axially-extending set screw it. The plate m corresponds in area with the flanged end of the hub, thus affording a groove for the reception of the orificed neck at the fulcrumed end of the crank arm 7, which, of course, in assembling, is positioned on the hub before the application of the'plate m. A dog or pin 2" extends into a socket in the neck of the crank army and is forced outward by a spring y". At 70 and Z are ratchet teeth in the hub adapted to engage the dog 6 and prevent forward movement of the crank relative to the shaft. One of these teeth Z, is located in that part of the periphery of the hub nearest the center of the shaft while the. other tooth is is located in that part of the periphery of the hub farthest from the center of the shaft.

The operator turns the crank arm backward, relative to the shaft, until the dog 5 enters the ratchet tooth 70; Turning the crankforward will start the machine with a long crank. After the desired speed has been reached the operator holds the crank stationary while the shaft makes one half revolution, when the dog t' enters the ratchet tooth Z. lhe crank is now in position for a short arm.

' The difference in length between the long and the short crank of the construction of Figs. 1, 2 and 3 may readily be seen to equal twice the distance between the center of the shaft a and the center of the bearing (2. In the constructionof Figs. Land 5, the difference in length between the long and the short crank will equal the difference between the shortest and the longest radius of the hub, or twice the distance between the center of the shaft and the axis of the crank.

7 nearest to the shaft center and therefore affords a short crank arm.

' Having now fully described our invention what we claim and desire to protect by Letters Patent is:

1. An adjustable crank construction comprising a crank shaft, a crank arm turnable freely in one direction independently of the shaft and also movable relative'to the shaft to vary the distance between the shaft and the free end of the crank arm, and locking connections between the shaft and crank arm adapted to maintain the crank arm in fixed relation to the shaft in either of its relative positions in the turning movement of the crank arm in the opposite direction.

2. An adjustable crank construction comprising a crank shaft, a crank arm, turnable shaft, thereby effecting the reversal of the positions ofthe two axes relative to the free end of the crank arm, and interlocking means adapted to hold the shaft in fixed re lation to the crank arm in the rotation of the latter in the opposite direction to enable the shaft to be driven by the crank arm.

An adjustable crank construction comprising a driven crank shaft, a hub attached to said shaft, a driving crank arm rotatively attached to said hub, the center of rotation not coinciding with the center of the crank shaft, and a dog and ratchet teeth, one turning with the shaft and the other with the crank arm, adapted to lock the crank arm to the hub in either of two positions, these positions being adapted to produce one a long and the other a short stroke of the crank. o

5. An adjustable crank construction comprising a driven crank shaft, a hub attached to said shaft, a driving crank arm rotatable on the hub on an axis not coincident with the center of the crank shaft, and means to lock-the crank arm to the hub. when the crank arm is turned to bring nearest its free end either its own axis or the axis of the shaft. i

6. An adjustable crank construction comprising a driven crank shaft, a hub attached to said shaft, a driving crank arm rotatable on said hub on an axis not coincident with the center ofthe crank shaft, and complementary locking devices on the hub and crank arm arranged to position the crank arm fixedly relative to the shaft at different positionsof the crank arm about its axis on the hub.

7. An adjustable crank construction comprising a crank shaft, a hub attached to said shaft, a crank arm freely rotatable backwardly on said hub on an axis not coincident with the center of the crank shaft, and means to arrest the forward motion of the crank arm about its axis on the hub at a plurality of positions corresponding to dif ferent radii from such axis of rotation, thereby causing the crank arm, when thus arrested at different positions, to drive the not coincident With-the center of the crank shaft, and locking means adapted, in the forward turning movement of the crank arm, to lock the hub to the arm at different distances from the free end of the latter.

9. An adjustable crankconstruction comprising a driven crank shaft,va. driving crank armfreely revoluble in one direction independently of the shaft and also movable relatively to the shaft to vary the distance between the shaft and the free end of the crank arm to provide a relativelong or short effective length of crank arm, and means to maintain the crank arm When in either position in fixed relation to the shaft in the turning'movement ofthe crank arm in the opposite direction.

10. An adjustable crank construction comprising a driven crank shaft, a driving crank arm, turnable independently of the shaft on an axis not coincident with the axisof the shaft, and means to lock the crank arm from rotation in one direction relative to the shaft in a plurality of positions of the crank arm Copies of this patent may be obtained for five cents each,.by addressing Washington, D. G.

about the first named axis, thereby permitting thecrank arm to turn about the axis of theshaft and drive the same.

11. An adjustable crank construction comprising a driven crank shaft, a driving crank arm freely rotatable, in one direction independent of the shaft on an axis independent of theaxis of. the shaftthereby effecting'the reversal of the positions of the two axes relative to the free end of the to hold the shaft in fixed relation to the crank arm in-the rotation of the latter in the opposite direction.

12. .An adjustable crank construction comj pr sing a crank shaft, a crank arm movable relatively to the shaft to vary the distance between the axis of theshaft and the free crank arm is held from rotation with the,

shaft.

In testimony ofwhich invention, we have hereunto set our hands, at Poughkeepsie, on

this 2-1 day of February, 1914. i r 1 MEREDITH LEITCH. V SELDEN H. HALL, Witnesses:

CHARLES L. POWELL, H. C, BEOKMAN.

the Commissioner of Patents, 

